(V)/Hydrotalcite, (V)/Al2O3, (V)/TiO2 and (V)/SBA-15 catalysts for the partial oxidation of ethanol to acetaldehyde

• High activity found for V/TiO2 catalyst in the partial oxidation of Ethanol.
• First use of a (Vanadium)/Hydrotalcite catalyst for the partial oxidation of Ethanol.
• Novel 1,3,5 Trioxane production from the ethanol oxidation.

Vanadium-based catalysts have been investigated in the partial oxidation of ethanol to acetaldehyde with the aim of understanding relationship between vanadium structure and acetaldehyde productivity. Hydrotalcite, Al2O3, TiO2 and SBA-15 with and without a 5% of vanadium content were prepared to study the oxidative dehydrogenation of ethanol. They were characterized by XRF, TPR (H2), NH3-TPD, CO2-TPD, RAMAN, UV-vis, Nitrogen physisorption, XRD and SEM. The most easily reducible catalysts (as determined by TPR) were the most active ones. In the low temperature region (150 °C), the most active catalyst was the V/TiO2 which presented stable activity in the production of acetaldehyde up to TOS = 200 h. On the contrary, in the high temperature region (250 °C), the most active catalyst was the V/Al2O3catalyst. The most promising result was obtained over V/TiO2 catalyst that afforded a total ethanol conversion of 60.4%wt. and a selectivity to acetaldehyde of 76.2%wt. at TOS = 164 h and T = 150 °C. Also, hydrotalcite was tested for the first time for this type of reaction providing a conversion lower than 7%wt. with a selectivity of 100%wt. to acetaldehyde at T = 150–225 °C.

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